Description:

The goal of the trial was to evaluate treatment with a Mediterranean diet compared with a control diet among patients at high cardiovascular risk.

Hypothesis:

A Mediterranean diet will prevent adverse cardiovascular events.

Study Design

Randomized

Parallel

Patient Populations:

Patients were eligible to participate if they had diabetes, or at least three of the following risk factors: hypertension, smoking, elevated low-density lipoprotein cholesterol, low high-density lipoprotein cholesterol, overweight or obesity, or a family history of premature coronary heart disease

Number of screened applicants: 8,713
Number of enrollees: 7,447
Duration of follow-up: Median 4.8 years
Mean patient age: 67 years
Percentage female: 59 years

A Mediterranean diet is characterized by high intake of olive oil, fruits, vegetables, and cereals, a moderate intake of fish and poultry, and a low intake of dairy products, red meat, processed meats, and sweets.

Concomitant Medications:

At baseline, 49% of participants were taking an angiotensin-converting enzyme inhibitor, 21% a diuretic, 41% a statin, 30% an oral hypoglycemic, and 19% an antiplatelet agent.

Principal Findings:

Overall 7,447 patients were randomized. The mean age was 67 years, 59% were women, 82% had hypertension, 50% had diabetes, 14% were current smokers, mean body mass index was 30 kg/m2, and mean waist circumference was 100 cm.

The primary outcome of cardiovascular death, myocardial infarction, or stroke occurred at a frequency of 8.1 events/1,000 person-years in the Mediterranean diet plus olive oil group (adjusted hazard ratio [HR] vs. control = 0.69, p = 0.008), 8.0 events/1,000 person-years in the Mediterranean diet plus nuts group (adjusted HR vs. control = 0.72, p = 0.03), and 11.2 events/1,000 person-years in the control diet. Obese patients appeared to derive more benefit from a Mediterranean diet than nonobese patients (p for interaction = 0.05).

Interpretation:

Among patients at elevated risk of cardiovascular disease, a Mediterranean diet was effective at reducing the composite endpoint of cardiovascular death, myocardial infarction, or stroke at a median follow-up of 4.8 years. A Mediterranean diet was also effective at reducing the incidence of stroke compared with a control diet. Mediterranean diet supplemented with extra-virgin olive oil or nuts seemed to be equally effective at reducing adverse events. This study complements the Lyon Heart Study, which documented the benefits of a Mediterranean diet when used for secondary prevention of cardiovascular disease events.